<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    var info = {
      name: "why",
      age: 18,
      friend: {
        name: "kobe",
        age: 30
      },
      running: function () {
        console.log("running")
      }
    }

    console.log(info.name)
    console.log(info.friend.name)
    info.running()

    info.age = 25
    info.running = function () {
      console.log("I am running")
    }
    console.log(info.age)
    console.log(info.running())

    info.height = 1.88
    info.studying = function () {
      console.log("I am studying")
    }
    console.log(info)

    delete info.age
    delete info.height
    console.log(info)

  </script>
</body>

</html>